This invention relates to a system for measuring sidestream smoke, and more particularly to a system which continuously and optically senses sidestream smoke drawn past a sensor.
In recent years there has been an increased interest in the amount of sidestream smoke produced by a cigarette. To develop cigarettes which produce less sidestream smoke, it is necessary to develop a system which can quantify the smoke produced by the cigarettes.
One prior attempt to quantify the sidestream smoke produced by cigarettes involved collecting the smoke on Cambridge filters designed to collect mainstream smoke. Once the smoke has been collected, a complex procedure is required to extract, analyze, and weigh the smoke components. Also, this procedure does not permit continuous or instantaneous measurements to be made.
Another attempt to quantify the amount of sidestream smoke produced by cigarettes, described in U.S. Pat. No. 4,589,775, involved accumulating sidestream smoke in a chamber having a sealed top. Light emitted from an LED was transmitted through the accumulated smoke and received by a detector. One drawback associated with accumulating the smoke is the resulting flow of combustibles to the cigarette. The combustible compounds in the smoke may circulate near the cigarette, affecting the cigarette burn, and changing the chemistry and test conditions. Also, this procedure measures the accumulated smoke in the chamber rather than measuring the sidestream smoke produced at any particular instant.
It would be desirable to provide a system for measuring sidestream smoke continuously and instantaneously. It would also be desirable to provide a system which does not affect the burning conditions of the cigarettes under test.